hi , since replacing the relief valve my boiler has become noisy , it sounds like a pulsing hum from the pump . it works ok but the pressure rises from 2 to 3 ( I think that's normal but not sure ). any advice gratefully received thanks.
ravenheat 120t lo nox combi noisy
- Thread starter lvjlo01
- Start date
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You say the pressure rises from 2 to 3, does that mean your pressure, when the system is cold, is 2 bar. That is a bit high 1.5 is the most you need, about 1.2 is better. The pressure rising to 3 is likely to open the PRV and get dirt under the seating, as you've just fitted a new one it would be prudent to sort this or you may well need another one very soon.
thanks Mick,
yes the pressure is set at 2 but I did lower it to about 1.5 , this gradually rose to just over 2 as the heating was on . when it goes any higher I drain some water back down to 1.5 . I never had this problem before the valve went faulty
yes the pressure is set at 2 but I did lower it to about 1.5 , this gradually rose to just over 2 as the heating was on . when it goes any higher I drain some water back down to 1.5 . I never had this problem before the valve went faulty
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It seems to me that your expansion vessel is faulty or needs repressurising. Thats probably what caused your PRV to need changing.
Pressure at 1.5 cold should rise to about 1.8 hot.
See the FAQ on this site for instructions to check and repressurise the EXV.
Tony Glazier
Pressure at 1.5 cold should rise to about 1.8 hot.
See the FAQ on this site for instructions to check and repressurise the EXV.
Tony Glazier
thanks tony, it wasn't so much the pressure that bothered me but the pulsing noise although the pressure will need to be addressed. Jim
yes I've bled the pump but haven't checked the cap , is that on the top of the pump?
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